Name:Name for the output velocity curve.

Source:Source for the output velocity curve.

Seismic Datum: The starting datum of the seismic.  This is used to determine the bulk shift when displaying tops on the seismic. This field will be populated if the value has already been entered for the project. This should not be changed.

Replacement Velocity: The velocity used for data that appears before the initial velocity curve entry.

Make it the active velocity curve: When this is turned on, the new velocity curve becomes the active curve for the selected well.  The active curve is used to place tops and curves on the seismic.